This invention relates to specific affinity reagents.
Specific affinity reagents (reagents in which a substance having specific affinity for a class of cells is coupled to a reporter group) are described in many patents and publications. (As used herein, "specific affinity" refers to the ability of a substance to bind to one substance or class of cells and to substantially fail to bind to other substances or classes of cells; "reporter group" refers to a substance which is delivered to the specific substance or cells by the specific affinity portion of the reagent, for a diagnostic or therapeutic purpose; examples are radioisotopes, paramagnetic contrast agents, and anti-cancer agents.) For example, Schall U.S. Pat. No. 4,152,411 and Hirschfeld U.S. Pat. No. 4,166,105 describe in vitro specific affinity immunoassay reagents in which polylysine is attached to an antibody and to multiple labels, e.g., fluorophores. Schall also generally mentions "spin labeled compounds [and] radiolabeled compounds".